Good pointers! My view on this is that if one wants to avoid lack of motivation, or art block, is to draw something every single day and also to have deadlines for your own work. If I feel lack of motivation it is usually after a large project and it can sometimes be daunting to work from a blank piece of white paper again. It is also a good idea to have some side projects you can work on as a warm up to the larger projects. Warming up in art is very important and one shouldn't forget that, much like stretching before doing sports. If nothing works, take a walk outside or focus on some other hobby for an hour or two, but make sure you come back to your pen and paper later in the day!